Question

how work become negative ​

Answer 1

Answer:

work becomes negative when the angle between the applied force and direction of movement are in opposite directions......eg. friction

we know

Work = f × s × cos(theta)

now if force and displacement are in opp. dirctions, angle between them is 180°.....and cos180 is -1

so

work = f × s × cos180

f × s × (-1)

-f•s

thus giving you negative work